Ground Systems
 

Visual Impact Analysis for the Berkeley Ground Station

   
  
Project Description
  
In support of the HESSI mission, NASA has provided funding for the installation of the Berkeley Ground Station, which comprises a satellite tracking antenna, about 10 meters in diameter. This antenna is proposed to be deployed on the knoll known as Goat Barn Rim Research Facility Reserve Site in the 1990 Long Range Development Plan and is located approximately 200 ft. downhill from the Silver Lab and MSRI. The proposed dish pad would be about 44 ft. on a side and the top of the dish would be about 40 ft. above ground. The visibility of the dish from various campus and nearby local sites (Panoramic Hill, LBNL, Botanical Garden), and regional sites (lower campus, downtown Berkeley, etc.) has been investigated. A consultant, ArchView Media, has prepared a visual analysis to address this impact. Shown below are 9 visualizations from different directions toward the proposed location of the Berkeley Ground Station.
  
 
View from Botanical Garden Parking Lot View from Downtown Berkeley
View from Panoramic Hills Area View from Panoramic Hills Area
View from South Side of Botanical Garden View from LBNL
 
 
Site Development
 
Shown below are two polar diagrams that illustrate passes of HESSI over the Berkeley area. These diagrams represent the so-called station mask for the Berkeley Ground Station. The outermost circle is the local horizon at zero degrees elevation, as seen from the antenna site. North is up and West is to the left. The center corresponds to the zenith at 90 degrees elevation, while the circles in between are spaced 10 degrees in elevation. The brown areas are the horizon obstruction contours, as seen from the antenna site, and the blue traces are the typical trajectories that the HESSI spacecraft will follow across the sky during a period of six days. HESSI will travel from west to east. It is a mission requirement that data are to be transmitted from the spacecraft to the ground station as soon as the elevation angle is 5 degrees. This corresponds to a point half way between the outermost circle and the next inner circle. The first of the two polar diagrams shows the present situation with all trees in place. The project requires removal of a number of eucalyptus trees of various size in the southwest, south, southeast and east since these trees will cause absorption of the high-frequency transmissions from the spacecraft to the ground station at low elevation angles. The second polar diagram shows the station mask with these eucalyptus trees removed.
 
 

Station Mask - no trees removed 
  

 Station mask with a number of trees removed
  
   
Color Options
 
The antenna pedestal and the outside surface of the dish will be painted in colors that will blend in well with the surroundings, in order to minimize the visual impact of the facility on the environment. The inside surface of the dish needs to be painted in white color to avoid overheating of the dish and the sensitive receivers during daytime. The dish will be pointed up into the sky most of the time in the stow position. A sample collection of available colors is shown below.
 
 
 
 
No. 24417 
No. 34424 
No. 34491 
 
 
 
 
 
 
No.34533 
No. 34554 
No. 24670 
     
No. 24516  No. 34672 
 
 
 
Schedule
 
Construction at the site needs to begin on September 1, 1998 and be will be by June 30, 1999 to maintain the time schedule of the mission. Engineering, design and bidding for the site work will commence in parallel with the environmental impact studies. The preparation of the antenna site comprises removal of eucalyptus trees, casting of the concrete foundation, paving of an area around the antenna base, reinforcement of the access road, and installation of utilities, drainage fencing and lighting. Delivery of the antenna system is expected for July of 1999. The pedestal will be erected first. The parabolic reflector dish will be assembled from individual segments and will then be mounted on the pedestal. Installation of a similar antenna is shown in the photograph below.
 
 
 
Typical antenna construction scenario, photographed in Alaska